1. Field of the Invention
Method for improving results of hydraulic fracturing in heterogeneous reservoirs. More specifically method is provided for preventing fluid from entering a well during or soon after hydraulic fracturing of an offset well completed in the same reservoir.
2. Description of Related Art
Hydraulic fracturing in unconventional reservoirs has increased in many parts of the world in recent years. Large amounts of fracturing fluid may be injected into a well in an effort to open more rock to allow hydrocarbons to be produced from the reservoir. Hydraulic fractures in conventional reservoirs (that are not naturally fractured) are formed in a preferred direction and the fracturing fluid leaks from a plane in fractured rock. Fracturing fluids do not move for long distances away from the confined vertical fracture. In contrast, in unconventional reservoirs the rock is often naturally fractured and when a hydraulic fracturing treatment is performed, fracturing fluid may flow far away from the well being fractured in different directions.
It has been observed in the field that fracturing fluids from fracturing treatments in offset wells in various directions may be produced into a producing well in the same reservoir or reservoir fluids may be temporarily produced at a higher rate. This is a disadvantage, because fracturing fluid or water near the producing well may decrease production rate of hydrocarbons and may require disposal of additional water.
What is needed is a simple and inexpensive method of preventing fracturing fluid from offset wells or additional reservoir water flowing into a producing well in the same reservoir as another well is being fractured.